A: What’s your suggestion if I want to be a singer? I want to drop out of school and start trying my luck at pubs.

B: If you are interested in becoming a professional musician, a degree in music performance may be just the ticket.

Note: This idiom means “just the right thing.” “Ticket” in this “just what is needed” sense include political “tickets” (roster of one party’s candidates), tickets for meals at soup kitchens given out by charities (a theory supported by the existence of the 18th century phrase “that’s the ticket for soup”), or a winning lottery ticket. It might just reflect the general sense of “ticket,” common since the 17th century, meaning “guarantee of some kind of benefit,” also found in such phrases as “ticket to success” and “write your own ticket.” Anyway, it’s exactly what one wants and feels perfect for the moment.